Pouring trough



May 17, 1932.

Original Filed Nov. 7, 1928 F. G. CARRINGTON POURING TROUGHl 2 Sheeis-Sheet l l i- Lplmxllwl A :NVEN-ron F6. CARR/NG TON ATTORNEYS Patented May 17, 1932 UNITED -s'rlvrr-:s

PATE

Nr' OFFICE FRANK G. CARRINGTON, F ANNISTON, ALABAILSBIGNOB T0 FERBIG ENGINEERING' CQMPANY, A GORPORATION 0F DELAWARE rouame 'rnooen Original application led November 7, 1928, Serial No. 317,817. Divided and this application led July 84,

jcation Serial No. 317,817, iled November 7, 1928, for process of casting metal centrifu gally, of which this application is a division.

The method of centrifugal casting in most commonl use comprises pouring molten metal into a rotating horizontal cylindrical mold from an end-pouring trough and` building up the casting helically by longitudinally moving the mold and trough relative to each other. During this operation the metall is subjected to various forces. The first is the force impelling it along the trough. This, however, is partially compensated for bythe relative movement of the mold and trough.

Usually, though not always, the trough remains stationary while the mold traverses it, but even if the trough moves while the mold remains axially stationary, this relative movement takes up a large part of the velocity of the stream. A second force to whichthe metal is subjected `results from the rotation of the metal when it is caught up by the spinning'mold. A third force is thel cen'- trifugal force set up in the meta-l by the rotation of the mold and its contents.

For castings with uniform walls, it is particularly essential that the longitudinal How of the metal be neutralized as quickly as possible to prevent a continued How down the mold. This neutralization is effected not only by the relative longitudinal movement of the mold and trough but by the centrifugal force which causes the metal to spreadout and partially reverse its direction of flow. The speed at which the mold is required to revolve in order to spread the metal is so great, however, that there is a' strong tendency toward surging and splashing. This tendency Lis aggravated by the fact that the metal is usually poured from the discharge end of the trough in a ribbon Whose longer dimension is transverse to the axis of the mold. As a consequence, this ribbon, on striking the mold, is whipped by the rotation into a tubular formation parallel to the molds axis. This whipping and change of Serial N0. 552,898.

direction creates surges and splashes which have a deleterious effect upon the cast product. The surges make for a pipe of non-uniform thickness, as there is apt to be a solidification of the cast metal before it has been distributed uniformly about the mold.

The relative longitudinal movement of the I' trough and mold establishes a time gradient for the deposition of metal at diHerent points along the length of the mold. In View of this time element, any splashing means that the metal l within a given area is not contemporaneously cooled. For instance, those drops that splash upon a section which has not yet received the metal solidify prior. to solidification of the stream which is subsequently poured upon that section. Conse# quently these drops do not fuse into the body "I of the pipe when it is cast over them, and produce efects in the 4finished article, commonly called splashes.

u It is the object of the present .invention to reduce the surging and splashing of metal which occurs when using the present types of end-pouring troughs and to deposit the molten metal within the mold in such a manner as to. produce a better and more homogeneous casting.

I have attained this object by shaping the pouring spout of an lend pouring trough so that the stream of metal is narrowed and deepened, emerging from the spoutin the form of a fiat ribbon flowing on edge. Thus the metal strikes the mold edgewise with its dimension longitudinally of the moldl greater than its transverse dimension, quite the reverse of the situation resulting from the use of the ordinary end-pouring trough. In this way the rotating mold readily picks up and distributes the metal with little splash# ing or surging.

In the accompanying drawings in which I have illustrated certain preferred embodiments of my invention, Figure 1 is a diagrammatic showing of a pipe mold, trough and and spout mounted therein; Figure 3 is a 100 View along the line 3 3 of Figure 2, looking l in the direction of the arrows; Figure 4 is a sectional view along the line 4-4 of Figure 2 looking in the direction of the arrows; Figure 5 is a sectional view along the line 5-5 of Figure 4 lookingy in the direction of the arrows; Figure 6 is a view similar to Figure 4, with the exception of showing metal in the process of pouring and the formation of a casting within the mold; Figure 7 is an end view of the spout during a casting operation, showing the metal being poured therefrom.

Referring more particularly to Figure 1, there is set forth a conventional type of mold 1, rotatably mounted in a mold carriage 1, which latter is supported by suitable rollers 2. The mold is rotated by a motor 3 or other driving means actuating the mold through a train of gears 4. The rollers 2 run upon a track 5, mounted at an angle to the horizontal as indicated by the line 6. Appropriate means (not shown) are provided for moving the mold on the track 5.

There is also shown in Figure 1a ladle 7 which may be of any type, mounted upon a support 8. Cantilevered upon the support 8 is an end pouring trough 9. y A chute 11 fits within the trough 9 adapted to receive the metal from the ladle 7 and convey it to the channel of the trough 9.

At the beginning of a casting operation the mold carriage 1 is advanced up the inclined track 5 until the end of the trough 9 is ad jacent the bell end 12 of the mold. VIt is, of course, obvious that my invention is equally well adapted for use in the casting of plainend pipe, in which case the operation is commenced by pouring metal in the far end of the mold, corresponding to the bell end 12. Metal is discharged from lthe ladle 7 into the chute 11 and conveyed through the trough 9 to the bell 12, or far end, of the mold. After the bell, or far end, of the mold has been suiiieiently filled with metal, the carriage 1 begins to move down the inclined track 5. During this movement of the carriage, the metal builds up on the interior of the mold in helical laminations, the adjacent laminations coalescing as the casting proceeds. I

The foregoing is a general description of the structure and operation of centrifugal casting machines of the end-pouring type.

. I shallnow describe the changes which l have made in this structure in accordance with the present invention.

Referring more particularly to Figures 2` and 5, the trough 9 is composed of a casing 13 composed of one of the steels having a high melting point, preferably annealed, or other suitable refractory material, in the channel of which there is inserted a lining 14. This lining is preferably cast iron, but it may bev made up of one ofv the steels just mentioned, re clay, or some other appropriate refractory. The channel of the lining 14 is fairly wide, which facilitates the cleaning and removal of any metal that may remain after a casting operation. The spout may be formed as an integral part of the trough, and by the term spout is meant that part of the trough from `.which the stream of metal discharges intothemold. The shape of the channel of the lining 14 also reduces the surface in con,- tact with the stream of metal as compared to a narrower channel, which, together with the rate of flow of the stream induced by thc| inclined position of the trough, prevents any considerable escape of heat from the metal. It will be noted that the channel of the lining 14 of the trough is uniform along its length.

Jointed to the discharge end of the trough by any suitable means to provide a liquidtight connection, is a spout 15. The composition of this spout may be cast iron, a high melting point steel, or a refractory such as lire clay. Referring to Figure 4, it will be observed that the bottom of the spout is flush with thebottom of the casing 13 (although this may be inclined), and that a portion 16 of the spout extends Within the casing 13 and forms in effect a lining for that portion of the casing so occupied, and affords additional support. The channel of the section 16 is the same as the channel of the lining 14 as indicated at 17. But from the end of the casing 13 the base of the channel falls 'away as at 18, ending in a slot 19. As shown 1n Figure 2, the slot 19 flaresI toward its open end, but, under suitable conditions, itssides may be parallel. The sides of the channel converge as at 21 for a distance, and then (and substantially at the beginning of the slot 19), flare out as at 22. This forms a throat 23 increasing the effective depth of the channel, the functioning of which is to confine the metal and so prevent an ex ces sive lateral spread as the ribbon falls into the mold.

The effect of this configuration of the spout upon the stream of metal 25 is to constrict its width and increase its depth, thus forming a ribbon of metal flowing edgewise with lts larger dimension vertical, as shown in Figure 6. It will be observed that the level of the stream remains substantially that of the stream within the trough 9, but that the depth increases along the sloping portion 18. This .'shape of the stream is effected by the sloping the absence of these Wings and the slot 19, the metal would have a tendency to fall from the end of the spout in substantially a sheet that would be erpendicular to the longitudinal' axis of die mold. By my invention, however, the metal is poured in the form of a ribbon that is parallel with the longitudinal axis, and consequently prevents the surge which would-naturally result from the rotation of the metal when it strikes the mold.

Figures 6 and 7 show the form assumed by the metal as it leaves the spout. It will be observed that the stream is constricted in width at the moment it vfalls through the slot 19 of the spout?, and may be considered as formed of'laminations 24.- These laminations 24 readilyassume the altered shape 'produced by rotation of the metal, and easily take thefffnim of the tubular mass of -metal 26. Consequently any tendency of the metal x in the rear of the .slot 19. This tapering portion is gradually built up as the mold moves along the track 5 until it is uniform with the rest of the casting. The result v1s that the Vcast pipe is free `fromfthe splashes or solidified surges. v.

It is believed that the operation of my mvention may be readily comprchended from the foregoing description. Metal is deposited in the liner 14 and iiows through it to the The throat23 narrows the stream to the desired minimum. The velocity is reduced to approachthe rate of speed at which the carriage 1 travels. This tends to neutralize the force set up by the longitudinal movement of the carriage. N Furthermore. as above pointed out. the metal falls upon the mold in rather a ribbon-like -formation, which readily ad justs itself to the rotation with the mold after its longitudinal low in the trough. The result is that the stream of metal impinges upon the mold in a ormthat is best adapted to assume its new shape. This reduces surgingand splashing of the metal to a minimum, and obviates the deleterious effects that have attended the prior processes and apparatus.V

It Willbe readily seenv that my finvention constitutes a real advance over the `prior art in that the product resulting therefrom'y is free from the disadvantages that are now prevalent, these being principally a non-unil formity in thickness of the pipe and the fori mation of splashes. By the term effective depth as applied to the channel of the troughis meant the depth ofnrthat ortion of the channel which lies below th i level othe stream of metal flowing therein and which exempli vactually confines the flowing stream of metal. lThe total depth of the channel is thus to be distinhguished from its effective depth. As ed in Fig. 6 of the drawings, while the total` depth' of the channel may be substantially uniform throughout the restricted y and non-restricted ortions of the trough, the effective depth varles as indicated by the in- Withoutaltering` the underlying principles, and without departing from the true scope of my invention as defined in the appended claims, by which alone I Wish my invention to be limited. I claim: A

1. An apparatus for depositing molten metal in a rotating mold comprising a trough extending longitudinally within the `mo1d and having a terminal spout portion, a chanvnel in the trough having a slotted opening y creasing height of the flowing metal stream.

Within the spout portion, and means restricting the width ofthe channelso as to increase its effective depth adjacent and in advance of the slotted opening.

2. An apparatus for depositing molten metal in a rotating mold comprising a trough extending longitudinally within the mold and having a straight terminal spout portion, a-

channel in the trough having a slotted opening intersecting its bottom within the spout portion, and means restricting the width of if the channel to increase its effective depth vertically at a position adjacent and in advance of the slotted opening.

' 3. An apparatus for depositing molten metal in a rotating mold comprising a trough extending longitudinally within the mold having a straight terminal spout portion, an open channel in the trough opening' through the spout portion to the end ofthe trough, said channel having/a slotted opening intersecting its bottom extending from the end of the spout portion` longitudinally of the trough, and means on the spout portion projecting into the channel from opposite sides fective depth of the channel vertically relative to its Width at a position adjacent and in advance of the slotted opening.

,thereof so as to appreciably increase the ef- 4. 'An apparatus for depositing molten metal in a rotating mold comprising a trough extending longitudinally Within the mold vhaving a straight terminal spout portion for discharging )the metal stream flowing in the channel into the mold, and a channel in the trough having a slotted opening intersect` ing its bottom vvvithin the spout portion, said spout portion having its side walls adjacent and 1n advance of the slotted opening gradually converging in a' direction toward the 1 discharge end ofthe spout to increase the e'ective depth of the channel and having a. downwardly sloping bottom so related to the converging side walls that the level of the stream flowing therebetween is maintained substantially uniform.

In testimony whereof I aix my signature.

FRANK G. CARRINGTON. 

